Curcumin pretreatment attenuates myocardial ischemia/reperfusion injury by inhibiting ferroptosis, autophagy and apoptosis via HES1

The early restoration of hemodynamics/reperfusion in acute myocardial infarction (AMI) is an effective therapeutic strategy to reduce sudden death and improve patient prognosis. However, reperfusion induces additional cardiomyocyte damage and cardiac tissue dysfunction. In this context, turmeric-derived curcumin (Cur) has been shown to exhibit a protective effect against myocardial ischemia/reperfusion injury (I/RI). The molecular mechanism of its activity, however, remains unclear. The current study investigated the protective effect of Cur and its molecular mechanism via in vitro experiments. The Cell Counting Kit-8 and lactate dehydrogenase (LDH) assay kit were used to assess the cell viability and cytotoxicity. The contents of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase, glutathione (GSH)/glutathione disulfide (GSSG), total iron, ferrous iron, caspase-3 and reactive oxygen species (ROS) were measured using an appropriate kit. Western blotting was used to detect the expression of relevant proteins. The levels of apoptosis, mitochondrial permeability transition pore (MPTP) opening, and mitochondrial membrane potential (MMP) were detected by flow cytometry. The study findings indicated that anoxia/reoxygenation (A/R) injury significantly decreased cell viability, increased in LDH and caspase-3 activities, induced ferroptosis, increased apoptosis and overactivated autophagy. However, pretreatment with Cur or ferrostatin-1 (Fer-1, a ferroptosis inhibitor) significantly increased A/R-reduced cell viability, SOD, glutathione peroxidase activity, GSH/GSSH ratio and HES1 and glutathione peroxidase 4 protein expression; attenuated A/R-induced LDH, MDA, total iron, ferrous iron, prostaglandin-endoperoxide synthase 2 protein expression and prevented ROS overproduction and MMP loss. In addition, Cur inhibited caspase-3 activity, upregulated the Bcl-2/Bax ratio, reduced apoptotic cell number and inhibited MPTP over-opening. Furthermore, Cur increased P62, LC3II/I, NDUFB8 and UQCRC2 expression and upregulated the p-AMPK/AMPK ratio. However, erastin (a ferroptosis activator), pAD/HES1-short hairpin RNA, rapamycin (an autophagy activator) and Compound C (an AMPK inhibitor) blocked the protective effect of Cur. In conclusion, Cur pretreatment inhibited ferroptosis, autophagy overactivation and oxidative stress; improved mitochondrial dysfunction; maintained energy homeostasis; attenuated apoptosis; and ultimately protected the myocardium from A/R injury via increased HES1 expression.